ptools.io

PNG to WebP Converter

Convert PNG to WebP without uploading anything.

Runs entirely in your browser

Loading the tool…

Your file is opened by this page and never uploaded. It is not sent anywhere, and the page keeps working with the network off.

Opens on WebP output. This is usually the best conversion on this page for anything going onto a website: WebP keeps the transparency PNG has and is typically 25 to 35 per cent smaller for the same picture.

Every browser in current use has supported WebP for years, so the old reason to avoid it has gone. The remaining reason is everything that is not a browser: if the file is going into a document, to a printer or through an upload form that has not been touched since 2019, PNG is still the safer thing to send.

The quality slider matters here. WebP can be lossy or lossless, and this page encodes lossily by default, which is where the size saving comes from. For a logo with hard edges, push the quality up.

How to use it

  1. Choose a PNG file. Nothing is uploaded: it is read in this tab.
  2. The output format is already set to WebP. Change the size or quality if you want to.
  3. Press Download to save the converted picture.

Questions

Does WebP keep transparency?

Yes, which is the main reason to prefer it over JPEG when converting a PNG. Alpha is preserved and the file is still smaller than the PNG was.

Is WebP safe to use on a website?

Yes. Every browser in current use has supported it for years, including Safari since 2020. The place to be careful is outside the browser, where support is still uneven.

Is my picture uploaded anywhere?

No. The file is decoded, drawn to a canvas and re-encoded entirely by your own browser. This page is served with a Content-Security-Policy whose connect-src is none, so it is not permitted to open a connection at all. Photographs are the files people most often regret uploading, which is most of the point.

Can I resize while converting?

Yes, and that is why this is the resizer rather than a separate tool. The width and height are filled in from the picture you choose, so leaving them alone converts at the original size; changing them does both jobs in one pass and one re-encode.

The other conversions

The same tool opening on a different output format. Any of them will convert to any of the three once you are there.

Your data stays on your device

Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. You can load this page once, go offline, and it still works.

This page makes no requests at all, to anywhere. That is not a promise in the copy: it is a Content-Security-Policy header your browser enforces, and connect-src on it is none. Open the network tab and watch nothing happen.